Carburetor alloy color on 40 pumpers.

[bigbikerrick]

Hello folks , the PHF 40 carbs on my 85 LeMans are a dark ,greenish looking alloy(magnesium?) I have seen some others that are a more "normal" looking aluminum color, I am wondering were some of these carbs made of a different alloy, or are mine just seriously tarnished? Is there a way to brighten them up, or polish parts such as the float bowls, and the crank tops? They look kinda dingy in that drab greenish color.
Thanks Rick

[swooshdave]

Soda blasting should work.

[bigbikerrick]

I have one of those small handheld sand blasters from harbor freight, the ones with the little plastic media tank on top. Can I use that with regular old household baking soda?
Rick.

[Antietam Classic Cycle]

It's not dirt or tarnish, I think that's some sort of a surface treatment (anodizing?) done at the factory, maybe to keep corrosion at bay. I wouldn't remove it. 

[canuck750]

Hi Rick,

Yes ordinary baking soda will work. Harbour Freight also sells larger volumes of baking soda for pretty cheap. All you need to do is dump the soda in a plastic pail and get one of those Harbour Freight siphon spray guns (under $25 ), its just a rubber hose attached to a pistol grip sprayer that takes an compressed air fitting. Fit an air compressor to the siphon sprayer, jamb the rubber hose from the siphon sprayer into the pail of soda and blast away. Makes a heck of a mess, wear a face mask that protects your eyes. Sweep up the used soda and throw it away.

To polish the alloy you can use a buffer wheel and a white or red polishing compound. Harbour Freight sells the big wheels that fit on a bench grinder or the small wheels with a stem to fit in a power drill and they sell the polishing compounds.

I cleaned up these Delorto carbs on my Laverda a couple weeks ago, 1st I acid washed them, then soda and then a light polishing and finally an ultrasonic cleaning.

Before



After

[Aaron D.]

The dark green was original, as Charlie says. I think you would regret removing it.

[bigbikerrick]

Thank you for the responses, gentlemen. If the dark green is a protective coating applied at the factory, then I will leave them alone. I thought it was some form of corrosion or tarnish. I am glad I check here first before going  OCD crazy on the carbs, and probably soon regretting it!
Rick.

[lucky phil]

Thank you for the responses, gentlemen. If the dark green is a protective coating applied at the factory, then I will leave them alone. I thought it was some form of corrosion or tarnish. I am glad I check here first before going  OCD crazy on the carbs, and probably soon regretting it!
Rick.

You could buy Magnesium bodied Dellortos back in the day that were a light olive green, I actually had some. If they are Mag Dellorts then I would advise you to leave them as they are.

Ciao